距离地面200~600km之间的低地球轨道＇/span>Low Earth Orbit LEO）空间，是对地观测卫星，气象卫星，空间站等航天器的主要运行区域，但由于地球轨道环境存在原子氧、紫外辐射、粒子辐射、高真空、等离子体、热循环以及微流星体与空间碎片的风险，对航天器的使用寿命和稳定性存在严重威胁，其中原子氧、紫外辐射、高真空、真空热循环对航天器表面材料会产生严重的损伤效应，影响材料尺寸稳定性、物理性能及机械性能。其?/span>原子氧作丹/span>LEO环境中的主要组分，它具有很强的氧化性。当飞行器以轨道速度?/span>LEO低地球轨道中运行时，原子氧以4~5eV的动能撞击飞行器材料表面。原子氧与材料之间的相互作用会造成表面材料剥蚀以及材料性能退化，它对有机材料的腐蚀作用还会产生可凝聚的气体生成物，进而污染航天器的光学仪器及其它设备、/span>目前，原子氧效应研究已成为低地球轨道空间LEO环境效应研究的一个不可缺少的组成部分、/span>
Resonance.Ltd开发的原子氧效应地面模拟实验舱，采用采?/span>CO2激光加热分解产生原子氧束，可同时满足能量为5eV和通量丹/span>3~510^16 atoms/cm2/s的严苛条件，其试验结果与LEO飞行暴露试验结果符合程度很高，被认为是目前实现定性和定量进行原子氧效应地面模拟的**手段、/span>
Description:
ResonanceLtd.hasdevelopedsystems to exposespacecraftmaterials to thermal atomicoxygen and VUV-UV light thatsimulates lowearthorbit conditions. Oxygen atomsareproducedupstreamfromthe exposure chamberbyradiofrequencydissociationof O2.Atomicoxygen concentrations to10^15 atoms/cm^3 canbegeneratedwith thehighpowerRFX-500generator.This is comparable to an atomicoxygenfluxofroughly
2x10^16cm^2/sec(equivalent 5 eV atomicfluxmeasuredwith
Kaptondosimeter).
Theoxygendensityprofile across thematerialsamplecanbemeasured in-situwith theResonanceLtd.Atomic Oxygen DensityProfilerusing the techniqueofresonance absorption.
Resonance alsoprovides lightsourcesfrom30 to >1?00nm thatsimulatethesolarspectrum.TheAtomic Oxygen DensityProfiler and Solar Simulator Sourcescanbe easily adapted to existing atomicoxygen exposuresystems.
AOsystemsfromResonancehavebeenusedbyCanadian Space
Agencyby Stanford UniversityUniversityofTokyoLosAlamos
FEATURES:
SimulatesLowEarthOrbitErosion
Samples exposed to continuousstreamof thermal Oxygen atoms
HighFlux
Atomicoxygenfluxesup to 3 x10^19 atoms/cm2/sec
QuickTurn Around
Measurable erosionof Kaptonbyweight loss in ?hourTypical
sample exposuretime is 2hours
Solar Simulation
Calibrated Solarsimulationusing VUV UVand Visiblelight
sources anddetectors
No Interferents
Samples aredownstreamfrom activeplasma and arenot exposed to
uncontrolled ionsmetastablesor UVradiation asinplasmaashers
In-Situ AtomicOxygen DensityProfile
Atomicoxygendensityprofile ismeasuredbyresonance absorption
of VUV line
Thermal Controlled SampleHolder
Sampleholder canbeheatedto increase erosionrate.Thermal-vacuumcyclingof thesample is also available
